Apparatus for cooling inclosures



0ct.2, 1934.l W,J,MADDEN l Y i u ,975,l 65

APPARATUS FOR COOLING INCLOSURES Filed ocit.. 13, 193s :s sheets--sneef'i INVENTOR.-

ocr. 2, 1934. l w. J. MADDEN- APEARATUS FOR COOLING INCLOSURES :s sheets-sheet s Filed 001;. 13, 1933 Ffa EZ.

l N V EN TOR: mmm Jg Madam,

mlm!

WI TNESSES- TORNEYS.

Oct. 2, 1934. w. J.jMApDEN 41,975,165

APPARATUS FOR COOLING INCLOSURES Filed oct. 1s, 195s s sheets-sheet 2l INVENToR.- William J.' Mmm BY ATTORNEYS.

' WITNESSES.-

Patented Oct. l 2, 1934 UNITED STATES.

. PATENT OFFICE This invention relates to apparatus for cooling inclosures for the comfort of people assembled therein, and more particularly to novel means for controlling the temperature of the air within an inclosure to maintain s uch temperature within limits which are dependent upon the difference between the inside and outside temperatures. While the invention is applicable generally to the cooling of rooms for human occupancy, it is particularly useful in its application to railway passenger cars because of the extreme temperature changes to which a train of cars may be subjected in traveling from one place to another.

During very hot periods the human body accustoms itself to higher atmospheric temperatures, and relief from depressing heat may be obtained in a room which is relatively cool but maintained at a. temperature considerably above the base temperaturefor maximum human comfort under average conditions. For example, where the prevailing atmospheric temperature is in the neighborhood of 95 F., and a railway car is internally cooled to a temperature in the neighborhoodof F., persons entering the car will experience a chill or appreciable discomfort by reason of the extreme change; and upon leaving the car and returningto the outside atmosphere, one experiences an even greater discomfort, and the change may result in a momentary suiiocating sensation. Obviously, therefore, during very hot days unless the car cooling apparatus is constantly adjusted to changing conditions, the apparatus will not operate economically with relation to the comfort of the passengers. Moreover, manual adjustment of the temperature control devices is diflicult and generally unsatisfactory, especially when effected by unskilled operators.

The object of my present invention is to provide an automatic temperature control for air cooled inclosures, eliminating the above recited dimculties by the provision of thermostatic means responsive to temperature changes inside and outside the inclosures, and operating in accordance with a predetermined formula to give the desired cooling effect under varying atmospheric conditions.

Other more specific objects and advantages characterizing my invention will become apparent from the description hereinafter set forth of one example or embodiment of the invention, having reference to the accompanying drawings. Of the drawings: I Fig. I represents somewhat diagrammatically a. portion, of a' railway passenger car and cooling apparatus having temperature control means'of my invention.

Fig.'II represents an enlarged plan view of a part of the cooling system.

Fig. III represents an end view of the same; and, l

Fig.l IV represents an enlarged view of the thermostatic control means. s

In the drawings there is shown an example of my invention as applied to the cooling system o1' a railway passenger car. 'I'he details of the car, and the manner of incorporation of the car cooling apparatus therein being merely representative of one type of apparatus to which the invention may be applied, requireonly brief description. In the drawings there is shown in diagrammatic outline at 1 the interior passenger space of\a railway car. At each end of the car there is provided a radiator unit 2 which withdraws airfrom the body of the car, cools the air by contact with cooling surfaces and returns the air for recirculation through the passenger space. Each radiator unit 2 includes a motor 3 and a pair of blowers 4 with axial intakes which discharge air through the casing of the unit over cooling coils and then through a grille 5 into the interior passenger space.

In the illustrated example of myvinvention, ice water is used as the cooling medium and is pumped from a. cooling chamber 6 located beneath the car through supply lines 7 to each end of the car and through the radiator units 2.

`Relatively warm water is returned from the radiator units 2 at each end of the car to the cooling chamber 6 by a return pipe 8 which has branches 9 constituting spray pipes and disposed in the top portion of the cooling chamber 6 in such manner as to deliver a shower of water over cakes of ice in the cooling chamber. 'I'he ice water in the cooling chamber 6 is withdrawn from the chamber through a pipe 10 and a strainer 11 by means of apump 14; and the water is discharged from the pump 14 through a control valve 15 in a branch 1,6 of the Water supply line- 7 and then through a T-connection 17 where it divides, a portion going to each end of the car. In an obvious manner the circulation of ice water from the cooling chamber 6 through the radiator units 2 at each end of the car cools the air passing through such units, the cooling effect being dependent upon the rate of ow ofthe water in the circulatory system. A drain pipe is preferably provided near the cooling chamber 6, as shown at 18, for th'e purpose of draining the water'in the system when desired, the drain pipe being normally closed by a valve 19.

As clearly shown in Figs. II and III of the drawings, the control valve 15 adjacent to the water pump 14 is disposed within the branch 16 of the water supply vconduit and is situated in proximity to the water return conduit 8. The control valve 15 is automatically operated by the combined cumulative action of two thermostats 21, 22, one such thermostat 21 being shown at one side of the valve, and the other thermostat 22 being shown at the other side of it, exposed to the atmosphere.

In Fig. IV there is shown one method of combining the action of the thermostat 21 with the action of the thermostat 22 to control the movement of `the valve l5. 'I'he invention contemplates the use of many different types of thermostats, and the manner of combining the movement of one with the movement of the other admits of great variation. In the illustrated example of my invention, however, the thermostat 21 includes a temperature responsive element 23a which is disposed within the return pipe 8 and the movement of which is dependent upon the temperature of the water in the return pipe 8. such temperature being necessarily a measure of the temperature of the air in the passenger space 1 of the car. Desirably I employ a temperature responsive element 23a of the bellows type in 4which a sensitive liquid is employed. The ele-V ment 23a/ctuates a stem 24a which has at the end thereof a valve member 25 within the valve body 15 and which is guided in its movementby a packing gland 2'7. Movement of the element 23a is transmitted-in an obvious manner, through the stem 24a, to the valve member 25, causing the same to be seated or unseated, and controlling the rate of i'low in the water supply line. The action of the temperature responsive element 23a is modified or regulated by means of a spring 26a surrounding the stem 24a. By varying the degree of compression of the spring 26a the range of operation of the thermostat 21 may be adjusted to different limits.

The outside air thermostat 22 is generally similar in its nature to the water thermostat 21 described above, and includes a temperature responsive element 23h, exposed to the atmosphere, a -stem 24h, and a regulating spring 26h. The stem 24h is guided for movement oncolumns 28 and carries a't the end thereof a yoke 29 which surrounds the control valve 15 and which is slidably associated with .the columns 3U of the thermostat 21. The portion 31 of the yoke 29 which is disposed within the columns 30 of the water thermostat 21 bears upon the regulating spring 26a oi.' that thermostat.

With the arrangement described, it will be observed that the valve member 25 is operated primarily through the action of the water thermostat 21,'but is modified by the action of the' thery mostat 22, the latter thermostat operating upon the regulatory spring 26a of the former thermostat. In carrying out the principle of my invention, the outside air thermostat 22 is either of a different capacity from the water thermostat 21 or is so arranged or proportioned that for every three degrees Fahrenheit increase or decrease-in temperature of the outside air the point at which the water thermostat 21 operates is raised or lowered one degree Fahrenheit. This ratio or proportion may be accomplished by the use of different liquids in the temperature responsive elements 23a, 23h having different properties as to expansion and contraction under temperature changes.

mostat 21 is arranged to have substantially three times the effect of the air thermostat 22 in moving the valve member 25. This ratio is determined by the following formula:

T= txio 370 where T represents the desired temperature to be obtained in the interior of the inclosure to be cooled, t1 represents the base temperature for maximum human comfort under average conditions which may be considered to be 72 F., and O represents the prevailing temperature outside the inclosure. If it be assumed, for example, that the prevailing outside temperature is 97 F., the desired inside temperature will be represented by:

1 relating the water thermostat 21 to the outside air thermostat 22. It involves only a slight departure from the above stated mathematical formula to utilize apparatus of the character described in which a change of three degrees Fahrenheit in outside temperature results in a change of one degree Fahrenheit in the temperature setting of the water thermostat 21.

The operation of the above described apparatus will be apparent from its description. It is to be particularly noted that the temperature control is fully automatic, and that no manual adjustments are necessary to meet varying atmospheric conditions. In very hot weather, as the temperature of the air in the interior of the inclosure rises, the rate of flow of the cooling medium through the supply line 8 to the radiator units 2 increases to the point where the interior temperature reaches substantially the temperature obtained by applying the above recited Iormula, and thereupon the inclosure is maintained at the desired temperature until there is a further change in the outside temperature. Changes in the interior temperature of the inclosure are reilected in the temperature oi the water returned from the radiator units v2 to the cooling chamber 6 in the present example of my invention, but it will be apparent that the temperature control means may be applied to many different types of cooling systems, and that there are other satisfactory methods of measuring the interior temperature of the inclosure.

In very hot weather a considerable saving in ice consumption will result from the practice of this invention, for the inclosure is not permittedto become cooled to an unnecessarily low temperature. Moreover, the rate of flow of water is reduced commensurate with the demand for cooling, and the pump 14 runs substantially continuously, eliminating the high maintenance costs incident to starting and stopping with manual operation.

While I have described my invention with reference to one particular form of cooling apparatus, and a particular arrangement of thermostats for controlling the rate of fiow of the cooling medium, it will be apparent that the invention is applicable to many different types of cooling apparatus, and that ,the thermostatic control changes outside'the inclosure, and an element re.

sponsive to temperature changes inside the inclosure, the movement of one such element being modied by the movement of the other element in accordance with a predetermined ratio.

2. In apparatus for cooling an inclosure, includingr a circulatory system having a cooling chamber, and supply and return conduits leading from said chamber to the inclosure to be cooled;

means for controlling the rate of flow in said supply conduit comprising an element responsive to temperature changes outside the inclosure, and an element responsive to temperature changes in said return conduit, the movement of one such element being modified by the movement of the other element in accordance with a predetermined ratio.

3. In apparatus forcooling an inclosure, including a circulatory system having a cooling chamber and a supply conduit leadingfrom said chamber to the inclosure to be cooled; means for controlling the rate of ow in said supply conduit comprising a valve, an element responsive to temperature changes in the air outside the inclosure,

and an element responsive to temperature changes in the airinside the inclosure, said elements-acting in combination to control the movement. of said valve in accordance with the temperature difference between the inside and outside air.

4. In apparatus for cooling an inclosure, including -a circulatory system having a cooling chamber and a supply conduit leading irom saidl chamber to the inclosure to be cooled; means for controlling the lrate of ilow in said supply conduit comprising a valve, athermostat responsive to temperature changes in the air outside the inclosure, and a thermostat responsive to temperature changes in the air inside the inclosure, one

such thermostat acting upon the. other to modify its range of operation.

5. In apparatus for cooling an inclosure, including a circulatory system having a cooling chamber, and a lsupply conduit leading from said y chamber. to the inclosure to be cooled means for controlling the rate of flow in said supply conduit comprising a thermostat responsive to temperature changes outside the inclosure, and a second thermostat responsive to temperature changes inside the inclosure, said thermostats acting in com bination to vary 'the rate of flow in Asaid supply conduit with the second thermostat having substantially three times the effect of the first thermostat.

' WILLIAM J.' MADDEN.

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